[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <05c311498fc8e7e9b2143c7b5fef6dc624cfc49f.1724226076.git.zhengqi.arch@bytedance.com>
Date: Wed, 21 Aug 2024 16:18:51 +0800
From: Qi Zheng <zhengqi.arch@...edance.com>
To: david@...hat.com,
hughd@...gle.com,
willy@...radead.org,
muchun.song@...ux.dev,
vbabka@...nel.org,
akpm@...ux-foundation.org,
rppt@...nel.org,
vishal.moola@...il.com,
peterx@...hat.com,
ryan.roberts@....com
Cc: linux-kernel@...r.kernel.org,
linux-mm@...ck.org,
linux-arm-kernel@...ts.infradead.org,
linuxppc-dev@...ts.ozlabs.org,
Qi Zheng <zhengqi.arch@...edance.com>
Subject: [PATCH 08/14] mm: copy_pte_range() use pte_offset_map_maywrite_nolock()
In copy_pte_range(), we may modify the src_pte entry after holding the
src_ptl, so convert it to using pte_offset_map_maywrite_nolock(). But
since we already hold the write lock of mmap_lock, there is no need to
get pmdval to do pmd_same() check, just pass NULL to pmdvalp parameter.
Signed-off-by: Qi Zheng <zhengqi.arch@...edance.com>
---
mm/memory.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index d3378e98faf13..3016b3bf0c3b0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1083,6 +1083,7 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
struct mm_struct *src_mm = src_vma->vm_mm;
pte_t *orig_src_pte, *orig_dst_pte;
pte_t *src_pte, *dst_pte;
+ pmd_t pmdval;
pte_t ptent;
spinlock_t *src_ptl, *dst_ptl;
int progress, max_nr, ret = 0;
@@ -1108,7 +1109,8 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
ret = -ENOMEM;
goto out;
}
- src_pte = pte_offset_map_nolock(src_mm, src_pmd, addr, &src_ptl);
+ src_pte = pte_offset_map_maywrite_nolock(src_mm, src_pmd, addr, NULL,
+ &src_ptl);
if (!src_pte) {
pte_unmap_unlock(dst_pte, dst_ptl);
/* ret == 0 */
--
2.20.1
Powered by blists - more mailing lists